The present invention relates to pulse plating rectifiers, and more particularly, to the parallel use of pulse plating rectifiers.
In a conventional pulse plating operation, several pulse rectifiers may be installed which are controlled by a common programmable logic controller (PLC). Typically, these pulse rectifiers do not include their own PLCs but are controlled by the common PLC. In operation a xe2x80x9crecipexe2x80x9d of pulse patterns may be programmed into the PLC and the single PLC controls the multiple pulse rectifiers. The xe2x80x9crecipexe2x80x9d typically defines the pattern of pulses which are to be generated by the pulse rectifiers and may differ from application to application.
Because the recipe is dynamic, in that it may change from application to application, typically, the common PLC controls all the pulse rectifiers which are to the power output over a single rectifier. The parallel pulse rectifiers typically are synchronized by the common PLC based on the particular recipe programmed into the PLC to avoid large circulating currents between the pulse rectifiers.
However, use of a single PLC may result in programming complexity as multiple pulse rectifiers carrying out differing recipes may be associated with the same PLC. The synchronization of the pulse rectifiers to the differing recipes would be controlled by the single PLC. Thus, in certain situations the ability to provide parallel operation of the pulse rectifiers may be limited by the capabilities of the common PLC. In such situations it may be possible to provide an additional PLC to control some of the pulse rectifiers but such a solution may necessitate maintaining an inventory of PLCs and/or pulse rectifiers which may need reconfiguration between operation of different recipes or recipe combinations to accommodate the differing recipes and recipe combinations. Thus, flexibility of a plating system may be reduced because a dedicated PLC is typically utilized to control a bank of pulse rectifiers.
In light of the above discussion, a need exists for improvements in plating rectifiers and/or systems utilizing plating rectifiers.
Embodiments of the present invention include plating pulse rectifiers which include a control computer and a power module operably associated with the control computer so as to output pulses based on control signals provided by the control computer. A master/slave mode selector is operably associated with the control computer so as to define the plating pulse rectifier as either a master plating pulse rectifier or a slave plating pulse rectifier. A data bus is operably associated with the control computer and configured to receive recipes to be loaded into the control computer and a sync bus is operably associated with the control computer and configured so as to transmit synchronization signals if the plating pulse rectifier is a master plating pulse rectifier and receive synchronization signals if the plating pulse rectifier is a slave plating pulse rectifier.
In further embodiments of the present invention, the control computer is configured to transmit a synchronization signal on the sync bus at the start of a pattern of a recipe loaded in the control computer if the plating pulse rectifier is a master plating pulse rectifier. Similarly, the control computer may also be configured to receive a synchronization signal on the sync bus and control the power module to output a pattern pulse of a recipe loaded in the control computer responsive to receiving the synchronization signal.
In particular embodiments of the present invention, the data bus comprises a RS-485 serial bus. Similarly, the sync bus may comprise a RS-485 serial bus.
In still further embodiments, the master/slave mode selector comprises a switch operably associated with the control computer. The switch may be configured to provide a first voltage level to the control computer if the plating pulse rectifier is a master plating pulse rectifier and a second voltage level, different from the first voltage level, if the plating pulse rectifier is a slave plating pulse rectifier. In such embodiments, the control computer may also be configured to read a voltage level provided by the switch and to define the plating pulse rectifier as a master plating pulse rectifier if the voltage level is the first voltage level and define plating pulse rectifier as a slave plating pulse rectifier if the voltage level is a second voltage level.
Furthermore, the master/slave mode selector may comprise a bit in a loadable control register in the control computer. In such embodiments, the loadable control register may be loadable from the data bus.
In still further embodiments of the present invention, a plating system may be provided which includes at least two plating pulse rectifiers. The at least two plating pulse rectifiers include a control computer, a power module operably associated with the control computer so as to output pulses based on control signals provided by the control computer, a master/slave mode selector operably associated with the control computer so as to define each plating pulse rectifier as either a master plating pulse rectifier or a slave plating pulse rectifier, a data bus operably associated with the control computer and configured to receive recipes to be loaded into the control computer, and a sync bus operably associated with the control computer and configured so as to transmit synchronization signals if the plating pulse rectifier is a master plating pulse rectifier and receive synchronization signals if the plating pulse rectifier is a slave plating pulse rectifier. One of the at least two plating pulse rectifiers is defined as a master plating pulse rectifier and the other of the at least two plating pulse rectifiers is defined as a slave plating pulse rectifier.
The sync bus of the master plating pulse rectifier and the sync bus of the slave plating pulse rectifier are also operably connected so that the synchronization pulse transmitted by the master plating pulse rectifier may be received by the slave plating pulse rectifier. Furthermore, the sync bus of the master plating pulse rectifier may be operably connected to only the sync of slave plating pulse rectifiers associated with the master plating pulse rectifier.
Furthermore, the plating system may further include a computer operably associated with the plurality of plating pulse rectifiers and configured to download recipes to the plurality of plating pulse rectifiers.
Further embodiments of the present invention provide methods, systems and computer program products for controlling plating pulse rectifiers by identifying one of the plurality of plating pulse rectifiers as a master plating pulse rectifier and identifying at least one of the plurality of plating pulse rectifiers, other than the master plating pulse rectifier, as a slave plating pulse rectifier. A recipe comprising a pulse pattern is downloaded to the master plating pulse rectifier and the slave plating pulse rectifier. A synchronization signal is transmitted from the master plating pulse rectifier upon initiating the pulse pattern of the recipe to the at least one slave plating pulse rectifier so as to cause the slave plating pulse rectifier to initiate the pulse pattern of the downloaded recipe.
In still further embodiments of the present invention, the synchronization signal is transmitted at the initiation of each pulse pattern in the downloaded recipe.
In additional embodiments of the present invention, the identification of one of the plurality of plating pulse rectifiers as a master plating pulse rectifier may be accomplished by setting a master/slave switch on the one of the plurality of plating pulse rectifiers identified as the master plating pulse rectifier to a master position and reading the position of the master/slave switch to identify the one of the plurality of plating pulse rectifiers as the master plating pulse rectifier based on the position of the master/slave switch. Furthermore, the position of the master/slave switch may be read at power up.
In yet additional embodiments of the present invention, the identification of at least one of the plurality of plating pulse rectifiers as a slave plating pulse rectifier may be accomplished by setting a master/slave switch on the at least one of the plurality of plating pulse rectifiers other than the master plating pulse rectifier to a slave position and reading the position of the master/slave switch to identify the at least one of the plurality of plating pulse rectifiers as a slave plating pulse rectifier based on the position of the master/slave switch.
In still further embodiments of the present invention, the synchronization signal is received at the at least one slave plating pulse rectifier and the pulse pattern of the downloaded recipe initiated responsive to receiving the synchronization signal. The pulse pattern may be initiated responsive to receiving the synchronization signal irrespective of whether a previous pulse pattern of the downloaded recipe has completed.
In other embodiments of the present invention, the recipe may be downloaded by transmitting the recipe onto a data bus operably associated with the plurality of plating pulse rectifiers and receiving the transmitted recipe at the master plating pulse rectifier and the at least one slave plating pulse rectifier. Furthermore, the recipe may be transmitted onto the data bus with a first address associated with the master plating pulse rectifier and also transmitted onto the data bus with a second address associated with the at least one slave plating pulse rectifier.
In particular embodiments of the present invention, the transmission of a synchronization signal from the master plating pulse rectifier upon initiating the pulse pattern of the recipe to the at least one slave plating pulse rectifier so as to cause the slave plating pulse rectifier to initiate the pulse pattern of the downloaded recipe may be carried out by transmitting a synchronization pulse on a sync bus operably associated with the master plating pulse rectifier,and the at least one slave plating pulse rectifier.
While the invention has been described above primarily with respect to method aspects of the invention, both systems and/or computer program products are also provided.